An image pickup apparatus capable of not only detecting whiteout or blackout but also effectively achieving exposure control. In the image pickup apparatus, an entire-screen brightness frequency distribution is detected based on a picked-up image signal. The image pickup apparatus calculates a first exposure control value from the entire-screen brightness frequency distribution. The image signal is divided into a plurality of small areas, and the brightness of each of the small areas is detected. The image pickup apparatus calculates a second exposure control value from the brightness. The image pickup apparatus calculates an exposure correction value based on the first exposure control value and the second exposure control value. An exposure value is calculated using the exposure correction value and an exposure value of the image signal. The image pickup apparatus performs exposure control of the image pickup section based on the calculated exposure value.